View to the south with 209 Mile Canyon entering from the lower right edge and joining the Colorado River just before the large flat island in Granite Park. The diagonal line starting about midway on the left edge (and trending toward the river in the distance) is the main branch of the Hurricane Fault. Movement along the fault fractures underlying rock making it easier for periodic rainstorms to erode away the surface. Thus, valleys and canyons tend to develop along fault lines.

   One of the side branches of the fault just grazes the river near the island in Granite Park, and then continues south-southeastward from there. Uplift to the east of this branch has brought Precambrian schist and granite to the surface to the left of the river just upstream from the island.
 
   Downstream from here the rock walls next to the river here are composed of the Tapeats to Supai Paleozoic layers. However, the strata generally slope upward to the south, and as a result the Precambrian basement rocks will begin to show up again – especially to the left (east) where they have been uplifted to the east of the Hurricane Fault. There are still patches of the lava flows near the river, but they are becoming steadily sparser as the river gets further from the volcanic source zones.

   In the western part of the Grand Canyon, the Hualapai Drainage system was eroding broad valleys down to the Esplanade Sandstone surface long before the Colorado found its new route across the Kaibab Plateau. As a result the outer rim formed by the Kaibab, Toroweap, Coconino, and Hermit formations has eroded back to where it usually cannot be seen from the river.